Inoreader added ads recently, and even disabling adblock didn't seem to fix this particular navigation bug: http://forum.inoreader.com/index.php?/topic/6615-strange-navigation-post-per-post/

This only fixes navigation by keyboard, specifically the 'n' and 'p' keys by forcefully scrolling to the current item a quarter of a second after the keypress. This is long enough for the scrolling animation to finish in most cases and should only be noticeable when the bug hits.

Navigation-by-clicking is untouched.